Not OP, but - I graduated in '95 and started working right away. Back then, the market and demand for developers was insane, and I ended up switching jobs - for 10-20% more every time - four times in four years. Then, right around 2000, the market crashed and I started interviewing again, and suddenly I had a really tough time finding anything: they brought up my short tenure at all my past jobs very negatively. I did finally find something, and have slowed down my job-hopping a bit (averaging 5 years per job now), but the "four jobs in four years, back in the late 90's" thing came up just last year during an interview - for a job that I didn't end up getting. In short - be careful, they're watching.
Personally I feel like an employer who is overly concerned with something like that (especially when it was so long ago) is a huge red flag.
People evaluate others based on their own experiences and ideas of success. If they feel that staying at one job for a long time is the utmost important factor above all else, what does that tell me about the kind of person they are and the kind of company they’re running? It tells me it’s probably a run of the mill mediocrity-factory full of people mostly just punching the clock every day. I’ve ignored these signs in the past and learned the hard way.
IMO places that have strong engineering cultures that are run by smart and driven people understand that your technical skill is what matters and aren’t going to hold it against you if you’ve hopped jobs to maintain your career growth, because they’ve most likely done the same thing themselves. Ambition recognizes ambition, and ambitious people HATE to stagnate.